1. Field of the Invention
The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus, such as a printer, photocopier, facsimile, and multifunctional machine incorporating several of these functions.
2. Discussion of the Background
Electrophotography is employed in various image forming apparatuses, such as printers, photocopiers, facsimiles, and multifunctional machines incorporating several of those imaging functions, in which a latent image is formed by selectively discharging a photoconductive surface, and then is developed into a visible image with toner electrostatically attracted to the photoconductive surface.
One electrophotographic imaging process commonly used is an intermediate transfer process that performs color printing by primarily transferring toner images of different colors to a single area of an intermediate transfer member to obtain a multicolor image, and subsequently secondarily transferring the multicolor toner image from the intermediate transfer member to a recording medium such as a sheet of paper. Typically, an intermediate transfer type image forming apparatus incorporates various pieces of imaging equipment to perform specific imaging functions, several of which are integrated into unitary assemblies or modules removably installed in a main body of the image forming apparatus.
FIG. 1 schematically illustrates a conventional electrophotographic image forming apparatus 2000 employing an intermediate transfer process with various imaging components enclosed in a main apparatus body 200.
As shown in FIG. 1, the image forming apparatus 2000 includes a set of multiple imaging units 201Y, 201C, 201M, and 201K (collectively designated by reference numeral 201) arranged in series in the middle of the apparatus body 200, each having a set of various imaging devices, such as a photoconductor, a charging device, a development device, etc., all of which are accommodated within a single housing for removable installation in the image forming apparatus 2000. The image forming apparatus 2000 also includes an intermediate transfer belt 210 looped along the series of imaging units 201 for rotation around a set of multiple primary transfer rollers 211Y, 211C, 211M, and 211K, with its outer surface in contact with a secondary transfer roller 212. Each primary transfer roller 211 is associated with one of the imaging units 201 to form a primary transfer nip with the photoconductor of the associated imaging unit 201. The secondary transfer roller 212 forms a secondary transfer nip with a roller located within the loop of the intermediate transfer belt 210.
In addition to the imaging and intermediate transfer units, the image forming apparatus 2000 includes an exposure unit 207 and a fixing unit 216, each disposed in an upper portion of the apparatus body 200, as well as a media tray 213 disposed at the bottom of the apparatus body 200 to accommodate a stack of recording media.
During operation, the image forming apparatus 2000 initially forms toner images of different colors on the photoconductors of the respective imaging units 201. In each imaging unit 201, the photoconductor has its outer surface initially charged by the charging device to a substantially uniform electric potential. The photoconductive surface is subsequently irradiated by the exposure unit 7 to form an electrostatic latent image thereon, followed by the development device applying toner to the latent image to render it into a visible toner image.
Each of multiple toner images formed through such imaging processes is then transferred onto the intermediate transfer belt 210 at the primary transfer nip, where the primary transfer roller 211 generates an electrostatic transfer field to attract toner from the photoconductive surface toward the belt surface. As the intermediate transfer belt 210 rotates to sequentially pass through the primary transfer nips, the multiple toner images transferred are superimposed one atop another in a single area of the belt surface to form a single multicolor image.
The combined toner image formed on the rotating belt 210 reaches the secondary transfer nip for transfer onto a recording medium fed from the media tray 13, where the secondary transfer roller 212 generates an electrostatic transfer field to attract toner from the belt surface to the recording medium surface. Thereafter, the recording medium bearing the powder toner image thereon is forwarded to the fixing unit 216, which fixes the toner image in place on the recording medium with heat and pressure, and then to an output tray disposed atop the apparatus body 200 to complete one printing cycle.
With continued reference to FIG. 1, the image forming apparatus 2000 has an openable/closable cover panel 310 to cover an opening defined in a front side of the apparatus body 200. The cover panel 310 is hinged along a front bottom edge of the apparatus body 200 and can rotate between an inclined, open position (represented by dotted lines) and an upright, closed position (represented by solid lines). As can be seen from the drawing, the cover panel 310 is combined with a media feeder assembly 320, wherein the secondary transfer roller 212 and several components involved in feeding recording media from the media tray 213 are assembled into a single unit detachably attached to an inner side of the cover panel 310 with certain holder and locking equipment, not shown.
The media feeder assembly 320 attached to the cover panel 310 is set to a proper operational position by closing the cover panel 310, and is separated from the apparatus body 200 by opening the cover panel 310. This enables a user to directly access the interior of the image forming apparatus 2000 through the opening solely by opening the cover panel 310, which facilitates mounting and dismounting of internal units (such as one containing the intermediate transfer belt 210) during repair or replacement, and removal of recording media jammed between the secondary transfer roller 212 and the intermediate transfer belt 210 during ordinary use.
Moreover, the media feeder assembly 320 can be detached from the cover panel 310 in the open position by disengaging the holder and locking members attaching it to the cover panel 310. This enables ready removal of internal components from the apparatus body 200 without interfering with or damaging the assembly 320, allowing for safe and easy maintenance of the image forming apparatus 2000.
One problem encountered by such an image forming apparatus with its process assembly attached to an openable/closable cover panel is that an inexperienced user often fails to properly mount the assembly to the cover panel and closes the cover panel without noticing the mounting failure. This often causes damage to holders and/or fasteners attaching the assembly to the cover panel, and the assembly improperly positioned with respect to surrounding components leads to malfunction or failure of the image forming apparatus.
Hence, what is needed is an image forming apparatus with a mounting mechanism with increased usability and functionality that allows a user to properly mount a process assembly to an openable/closable cover panel, and prevents damage to the image forming apparatus due to improper mounting of the assembly in the apparatus body.